feat: Flat import of markdown repo

This is a flat (without history) import of (some of) the content
from our markdown module.

We've imported this without history because the repo contains our
blog posts and showcases posts content prior to porting them to strapi.

Since this contains many images, it would balloon the size of this repo
to import the full history.

Instead, please refer to the history of the (archived) markdown repo
at: https://github.com/freesewing/markdown

markdown/dev/reference/macros/bartack/en.md

@@ -0,0 +1,28 @@
+---
+title: bartack
+---
+
+The `bartack` macro allows you to add a *bartack* marker to your sewing pattern.
+It is provided by the [bartack plugin](/reference/plugins/bartack/).
+
+<Example part="plugin_bartack" caption="Example of the bartack macro" />
+
+```js
+points.a = new Point(15, 15)
+
+macro('bartack', {
+  anchor: points.a,
+  angle: 30,
+  length: 15
+})
+```
+
+| Property     | Default    | Type       | Description | 
+|-------------:|------------|------------|-------------|
+| `angle`      | `0`        | `number`   | The angle under which to draw the bartack |
+| `density`    | `3`        | `number`   | Controls how close the stitches are togeter |
+| `length`     | `15`       | `number`   | Length of the bartack |
+| `nameFormat` |            | `function` | A method that receives the name of the path or point and should return the name for the cloned path and or point |
+| `prefix`     |            | `string`   | A prefix to apply to the names of the generated path and points |
+| `suffix`     |            | `string`   | A suffix to apply to the names of the generated path and points |
+| `width`      | `3`        | `number`   | Width of the bartack |